Voyager I and II

Morning Edition:

Once they've reached interstellar space, the Voyager spacecraft will also have a chance to deliver their golden cargo — the data records that include 116 pictures, along with sounds from Earth. The discs includes songs from Louis Armstrong, Beethoven, and a Navajo tribe.
And in Amoy, a language from eastern China, the records carry this message: "Friends of space, how are you all? Have you eaten yet? Come visit us if you have time."
It may seem risky to send an open invitation to the universe that tells alien races to stop by for a bite. But it's not as if Earth can send many invitations. That's because of the unique way our solar system's planets were aligned in 1977, when the Voyager craft were launched.
"That was an opportunity that happens every 176 years," Stone says, "to send a spacecraft past all four of the giant outer planets: Jupiter, Saturn, Uranus and Neptune."

The story on the radio mentioned that the computers on the spacecraft have enough memory for 8000 words.